feat: Update CLAUDE.md files, add docs

legalconsenthub-backend/CLAUDE.md

@@ -80,6 +80,7 @@ The application automatically seeds initial data on first startup:
    - Verify all element types render correctly
    - Ensure template sections excluded, spawned sections included
    - Hotspots: `ApplicationFormFormatService.kt`, `application_form_latex_template.tex`
+4. **Stateless** - Any implementation must support statelessness for horizontal scaling (multiple instances behind load balancer)
 
 ### Architecture Guidelines
 - **Service layer** - Business logic lives here
@@ -88,6 +89,10 @@ The application automatically seeds initial data on first startup:
 - **Mapper layer** - Separate mapper classes for DTO/Entity conversions
 - **Entity layer** - JPA entities with relationships
 
+### Code Quality Rules
+- **Never use @Suppress annotations** - Fix the underlying issue instead of suppressing warnings
+- **Controller methods must override generated interfaces** - All public endpoints must be in OpenAPI spec
+
 ### PDF Generation
 - LaTeX templates in `src/main/resources/templates/`
 - Thymeleaf for dynamic content